Biomedical subjects

W L Haskell

Publications and source records attributed to W L Haskell.

At least 19 recordsLinked to original sources

PubMed2001

The effect of soy protein with or without isoflavones relative to milk protein on plasma lipids in hypercholesterolemic postmenopausal women.

BACKGROUND: Clinical trial data and the results of a meta-analysis suggest a hypocholesterolemic effect of soy protein. The effect may be partially attributable to the isoflavones in soy. Few studies have examined the separate effects of soy protein and isoflavones. OBJECTIVE: The objective of this study was to determine the effect of soy protein and isoflavones on plasma lipid concentrations in postmenopausal, moderately hypercholesterolemic women. DESIGN: This was a randomized, double-blind, placebo-controlled clinical trial with 3 treatment groups. After a 4-wk run-in phase during which the women consumed a milk protein supplement, the subjects were randomly assigned to 12 wk of dietary protein supplementation (42 g/d) with either a milk protein (Milk group) or 1 of 2 soy proteins containing either trace amounts of isoflavones (Soy- group) or 80 mg aglycone isoflavones (Soy+ group). RESULTS: LDL-cholesterol concentrations decreased more in the Soy+ group (n = 31) than in the Soy- group (n = 33) (0.38 compared with 0.09 mmol/L; P = 0.005), but neither of these changes was significantly different from the 0.26-mmol/L decrease observed in the Milk group (n = 30). The results for total cholesterol were similar to those for LDL cholesterol. There were no significant differences in HDL-cholesterol or triacylglycerol concentrations between the 3 groups. CONCLUSIONS: The difference in total- and LDL-cholesterol lowering between the 2 soy-protein supplements suggests an effect attributable to the isoflavone-containing fraction. However, the unexpected LDL-cholesterol lowering observed in the Milk group, and the fact that there was no significant difference between either soy group and the Milk group, suggests that changes may have been due to other factors related to participation in the study.

Aged↗

PubMed2001

What to look for in assessing responsiveness to exercise in a health context.

PURPOSE: When attempting to assess responsiveness to habitual exercise in a health context, there is a wide range of issues that need to be addressed in order to provide science-based recommendations for use in evidence-informed health care delivery. Issues regarding responsiveness include characteristics of the exercise regimen or dose as well as characteristics of the response or effect. RESULTS: The exercise dose typically has been characterized by its type, intensity, session duration, and session frequency with the concepts of activity profile, activity volume, and accumulation over multiple bouts throughout the day recently added to these discussions. When establishing the dose for a designated outcome, specificity of the response in relation to exercise type needs to be considered. Understanding the role of intensity as a stimulus for change is critical because of the intensity-related biological responses to exercise, its role in exercise-induce medical complications, and the aversion many adults have to vigorous exercise. Receiving considerable attention is whether a higher intensity or greater volume of endurance-type exercise is more important in producing a variety of health-related benefits. To understand the potential role of accumulation of exercise, more information is needed on benefits derived from very short (< or = 5 min) bouts of exercise performed frequently as well as very long bouts (> or = 90 min) performed infrequently. CONCLUSIONS: When considering the response, it is important to establish the priority health outcomes, the relationship of the dose response for individual biological variables to the dose response for clinical outcomes, the basis for substantial interindividual variations in the response to a specific exercise dose, and the health benefit to health risk relationship for various doses of exercise. Scientific resolution of these issues will substantially facilitate the development and dissemination of appropriate guidelines for the use of exercise in promoting health.

Evidence-Based Medicine↗

PubMed2001

CHAMPS physical activity questionnaire for older adults: outcomes for interventions.

PURPOSE: To evaluate effectively interventions to increase physical activity among older persons, reliable and valid measures of physical activity are required that can also detect the expected types of physical activity changes in this population. This paper describes a self-report physical activity questionnaire for older men and women, developed to evaluate the outcomes of the Community Healthy Activities Model Program for Seniors (CHAMPS), an intervention to increase physical activity. METHODS: The questionnaire assesses weekly frequency and duration of various physical activities typically undertaken by older adults. We estimated caloric expenditure/wk expended in physical activity and created a summary frequency/wk measure. We calculated measures of each of these for: 1) activities of at least moderate intensity (MET value >/= 3.0); and 2) all specified physical activities, including those of light intensity. Six-month stability was estimated on participants not likely to change (assessment-only control group, physically active cohort). Several tests of construct validity were conducted, and sensitivity to change was analyzed based on response to the CHAMPS intervention. RESULTS: The sample (N = 249) comprised underactive persons (N = 173 from the CHAMPS trial) and active persons (N = 76). The sample was aged 65-90 yr (mean = 74, SD = 6); 64% were women, and 9% were minorities. Six-month stability ranged from 0.58 to 0.67, using intraclass correlation coefficients. Nearly all construct validity hypotheses were confirmed, though correlations were modest. All measures were sensitive to change (P < or = 0.01), with small to moderate effect sizes (0.38-0.64). CONCLUSIONS: The CHAMPS measure may be useful for evaluating the effectiveness of programs aimed at increasing levels of physical activity in older adults.

Aged↗

PubMed2000

Impact of a home-based walking and resistance training program on quality of life in patients with heart failure.

Patients with heart failure (HF) often have profound activity limitations and diminished quality of life (QOL) due to symptoms of dyspnea and fatigue. Although recent studies demonstrate positive physiologic and psychological benefits of low to moderate intensity, supervised, aerobic exercise training performed 3 to 5 days/ week for 20 to 40 minutes' duration, in a monitored setting, the efficacy of a home-based exercise program combining endurance and resistance exercise on symptoms and QOL, are unknown. This randomized controlled study examined the efficacy, safety, and adherence rates of a 3-month home-based combined walking and resistance exercise program on symptoms and QOL in 40 women and men aged 30 to 76 years with New York Heart Association class II to III HF. Baseline and 3-month evaluations consisted of a chronic HF questionnaire to assess symptoms and QOL and exercise capacity by symptom-limited treadmill exercise test with respiratory gas analysis. The exercise intervention improved fatigue (p = 0.02), emotional function (p = 0.01), and mastery (p = 0.04). Overall exercise adherence was excellent (90%) and there were no reported adverse events. A moderate intensity home-based combined walking and resistance program for patients with class II to III HF is safe and effective in reducing symptoms and improving QOL.

Adult↗

PubMed2000

[Sports, exercise and health. On the way into a new century].

In most countries throughout the world, except those affected by the HIV-Aids epidemic, populations are increasing in size, rapidly getting older, and becoming more sedentary. This combination, along with the adoption of unhealthy habits such as cigarette smoking and consumption of an animal-based rather than a plant-based diet, will result in chronic degenerative diseases becoming the most common cause of disability and premature death throughout the world during the first twenty-five years of this new millennium. As more and more populations acquire the technology that reduces the need to exercise for transportation, occupation or maintaining a household, lack of activity quickly becomes a major risk for coronary heart disease, stroke, hypertension and noninsulin dependent diabetes mellitus. This lack of activity appears to contribute to other disorders such as osteoporosis and selected site-specific cancers. In older persons, inactivity can become a major reason for loss of physical independence and a reduction in their quality of life. Public health approaches will be needed to reverse this trend of increasing "hypokinetic" diseases as the computer/communication revolution becomes worldwide. These public health programs will need to be supported by government and corporate changes in policies that provide time, facilities and incentives for maintaining an appropriately active life-style. The goal should be for all adults to perform at least 30 minutes of moderate to vigorous intensity exercise on most days.

Cardiovascular Diseases↗

PubMed2000

Methodologic issues in measuring physical activity and physical fitness when evaluating the role of dietary supplements for physically active people.

Physical activity and physical fitness are complex entities comprising numerous diverse components that present a challenge in terms of accurate, reliable measurement. Physical activity can be classified by its mechanical (static or dynamic) or metabolic (aerobic or anaerobic) characteristics and its intensity (absolute or relative to the person's capacity). Habitual physical activity can be assessed by using a variety of questionnaires, diaries, or logs and by monitoring body movement or physiologic responses. Selection of a measurement method depends on the purpose of the evaluation, the nature of the study population, and the resources available. The various components of physical fitness can be assessed accurately in the laboratory and, in many cases, in the field by using a composite of performance tests. Most coaches and high-level athletes would accept as very beneficial a dietary supplement that would increase performance in a competitive event by even 3%; for example, lowering a runner's time of 3 min, 43 s in the 1500 m by 6.7 s. To establish that such small changes are caused by the dietary supplement requires carefully conducted research that involves randomized, placebo-controlled, double-blind studies designed to maximize statistical power. Statistical power can be increased by enlarging sample size, selecting tests with high reliability, selecting a potent but safe supplement, and maximizing adherence. Failure to design studies with adequate statistical power will produce results that are unreliable and will increase the likelihood that a true effect will be missed.

Data Collection↗

PubMed2000

Complementary and alternative medicine use among elderly persons: one-year analysis of a Blue Shield Medicare supplement.

BACKGROUND: Large scale surveys in the United States and abroad suggest that 35-60% of adults have used some form of complementary/alternative medicine (CAM). However, no studies to date have focused on predictors and patterns of CAM use among elderly persons. METHODS: The population surveyed were Californians enrolled in a Medicare risk product that offers coverage for acupuncture and chiropractic care. Surveys were mailed to 1597 members in 1997 and responses received by 728 (51% response rate). Health risk assessment data were also obtained at baseline and 12-15 months following enrollment in the plan. Multiple logistic regression analyses were carried out to examine predictors of CAM use. RESULTS: Forty-one percent of seniors reported use of CAM. Herbs (24%), chiropractic (20%), massage (15%), and acupuncture (14%) were the most frequently cited therapies. CAM users tended to be younger, more educated, report either arthritis and/or depression/anxiety, not be hypertensive, engage in exercise, practice meditation, and make more frequent physician visits. Use of CAM was not associated with any observed changes in health status. Respondents also expressed considerable interest in receiving third-party coverage for CAM. Although 80% reported that they had received substantial benefit from their use of CAM, the majority (58%) did not discuss the use of these therapies with their medical doctor. CONCLUSIONS: Findings suggest that there is significant interest in and use of complementary/alternative medicine among elderly persons. These results suggest the importance of further research into the use and potential efficacy of these therapies within the senior population.

Aged↗

PubMed2000

Comparative effects of two physical activity programs on measured and perceived physical functioning and other health-related quality of life outcomes in older adults.

BACKGROUND: Although inactivity is an important contributor to impaired functioning and disability with age, little is known concerning how improvements in physical functioning and well-being in older adults vary with the type of physical activity undertaken. METHODS: One hundred three adults age 65 years and older, recruited via population-based methods, were randomized to 12 months of community-based, moderate-intensity endurance and strengthening exercises (Fit & Firm) or stretching and flexibility exercises (Stretch & Flex). A combination of class- and home-based exercise formats was used. Measured and self-rated physical performance along with perceived functioning and well-being were assessed pre- and postintervention. RESULTS: Fit & Firm subjects showed greater 12-month improvements in both measured and self-rated endurance and strength compared to Stretch & Flex subjects. Stretch & Flex subjects reported greater improvements in bodily pain, and Stretch & Flex men evidenced greater improvements in flexibility relative to Fit & Firm subjects. Although overall exercise adherence was high in both exercise conditions (approximately 80%), subjects in both conditions showed better adherence to the home- versus class-based portions of their exercise prescriptions. CONCLUSIONS: Community-based programs focusing on moderate-intensity endurance and strengthening exercises or flexibility exercises can be delivered through a combination of formats that result in improvement in important functional and well-being outcomes. This represents one of the first studies to report significant improvements in an important quality of life outcome-bodily pain-with a regular regimen of stretching and flexibility exercises in a community-based sample of older adults.

Activities of Daily Living↗

PubMed2000

Promoting physical activity: the new imperative for public health.

The aim of this essay is to provide an overview of initiatives designed to increase physical activity among different populations and in different settings, and to set the context for the major challenges that lie ahead. The decline in habitual physical activity with modernization, and the causal link between physical activity and health are briefly reviewed. The need to understand physical activity as a health behavior and examples of behavior change theories that have been applied to the promotion of physical activity are discussed. Diverse projects and campaigns in three countries, i.e. South Africa, Australia and the US, are highlighted. Common themes found in these physical activity initiatives include the development of a theory-driven research base, inclusion of behavioral and social scientists on multidisciplinary teams, and advocacy for environmental changes that promote physical activity. Within the next decade, research projects and national campaigns such as those described herein will yield important new findings on how to increase physical activity levels among targeted sectors of the population. The research agenda for the future includes development of both basic and applied research on physical activity, and the integration of theory across social, behavioral and biomedical disciplines.

Adult↗

PubMed2000

Compendium of physical activities: an update of activity codes and MET intensities.

We provide an updated version of the Compendium of Physical Activities, a coding scheme that classifies specific physical activity (PA) by rate of energy expenditure. It was developed to enhance the comparability of results across studies using self-reports of PA. The Compendium coding scheme links a five-digit code that describes physical activities by major headings (e.g., occupation, transportation, etc.) and specific activities within each major heading with its intensity, defined as the ratio of work metabolic rate to a standard resting metabolic rate (MET). Energy expenditure in MET-minutes, MET-hours, kcal, or kcal per kilogram body weight can be estimated for specific activities by type or MET intensity. Additions to the Compendium were obtained from studies describing daily PA patterns of adults and studies measuring the energy cost of specific physical activities in field settings. The updated version includes two new major headings of volunteer and religious activities, extends the number of specific activities from 477 to 605, and provides updated MET intensity levels for selected activities.

Activities of Daily Living↗

PubMed2000

A review of mind/body therapies in the treatment of musculoskeletal disorders with implications for the elderly.

BACKGROUND: A comprehensive, but not systematic, review of the research on complementary and alternative treatments, specifically mind/body techniques, on musculoskeletal disease was conducted at Stanford University. The goals of the review were to establish a comprehensive literature review and provide a rationale for future research carrying the theme of "successful aging." METHODS: Computerized searches were conducted using MEDLINE, PsychInfo, Stanford Library, Dissertation Abstracts, Lexus-Nexus, the Internet as well as interviews conducted with practitioners and the elderly. Mind/body practices evaluated were: social support, cognitive-behavioral therapy, meditation, the placebo effect, imagery, visualization, spiritual/energy healing, music therapy, hypnosis, yoga, tai chi, and qigong. Studies published after 1990 were the priority, but when more recent literature was scarce, other controlled studies were included. RESULTS: Mind/body techniques were found to be efficacious primarily as complementary treatments for musculoskeletal disease and related disorders. Studies provided evidence for treatment efficacy but most apparent was the need for further controlled research. CONCLUSIONS: Reviewers found a dearth of randomized controlled research conducted in the US. There is a lack of studies with which to determine appropriate dosage and understand the mechanisms by which many of the practices work. Anecdotal evidence, some controlled research, clinical observation, as well as the cost effectiveness and lack of side effects of the mind/body treatments make further investigation a high priority.

Aged↗

PubMed1999

Seven-year changes in physical fitness, physical activity, and lipid profile in the CARDIA study. Coronary Artery Risk Development in Young Adults.

PURPOSE: To relate seven year changes in physical fitness and physical activity in the young adult population to changes in the plasma lipid profile and to examine the influence of weight change on those relationships. METHODS: The participants in this observational study were the 1777 black and white men and women, ages 18-30 at entry into the Coronary Artery Risk Development in Young Adults (CARDIA) cohort, who completed a symptom-limited graded treadmill exercise test and had an overnight fasting blood draw at both the Baseline (1985-86) and Year 7 (1992-93) exams. CARDIA, a longitudinal study of the relationships of lifestyle and physiological variables to the development of coronary heart disease risk factors, consists of population-based cohorts in Birmingham, Alabama, Minneapolis, Minnesota and Chicago, Illinois and a cohort recruited from the membership of a large, pre-paid health care plan, broadly representative of the population, in Oakland, California. RESULTS: All race/gender groups experienced mean decreases in physical fitness and self-reported physical activity and increases in weight. Decreased fitness was associated with decreased high density lipoprotein-cholesterol (HDL-C), and conversely, increased fitness was associated with increased HDL-C. The correlation coefficients of change in fitness with change in HDL-C ranged from 0.17 in white men and black women to 0.24 in white women (P < 0.001 for all race/gender groups). Change in fitness was minimally correlated with change in low density lipoprotein-cholesterol (LDL-C) in all groups (r ranged from -0.09 in black women to -0.20 in white women), triglycerides (TG) in men and white women (r ranged from -0.10 to -0.15), and total cholesterol (TC) in white men and women (r = -0.11 and -0.15, respectively). The magnitude of these correlations was further reduced with adjustment for weight change. Correlations between change in activity and change in lipid and lipoprotein values were generally weak or nonexistent, except for the suggestion of a small, direct relationship with change in HDL-C in black and white women (r = 0.14 and r = 0.11, respectively). All of the weight change adjusted correlations were essentially unaffected by further adjustment for baseline fitness or activity and other covariates. CONCLUSIONS: Decreased fitness during young adulthood is associated with unfavorable changes in lipid profile, explained mostly by increased weight. Lack of association between change in activity and change in lipid profile observed in this study may be due, in part, to imprecision of activity measurement.

Adolescent↗

PubMed1999

A comprehensive and cost-effective preparticipation exam implemented on the World Wide Web.

Mandatory preparticipation examinations (PPE) are labor intensive, offer little routine health maintenance and are poor predictors of future injury or illness. Our objective was to develop a new PPE for the Stanford University varsity athletes that improved both quality of primary and preventive care and physician time efficiency. This PPE is based on the annual submission, by each athlete, of a comprehensive medical history questionnaire that is then summarized in a two-page report for the examining physician. The questionnaire was developed through a search of MEDLINE from 1966 to 1997, review of PPE from 11 other institutions, and discussion with two experts from each of seven main content areas: medical and musculoskeletal history, eating, menstrual and sleep disorders, stress and health risk behaviors. Content validity was assessed by 10 sports medicine physicians and four epidemiologists. It was then programmed for the World Wide Web (http:// www.stanford.edu/dept/sportsmed/). The questionnaire demonstrated a 97 +/- 2% sensitivity in detecting positive responses requiring physician attention. Sixteen physicians administered the 1997/98 PPE; using the summary reports, 15 found improvement in their ability to provide overall medical care including health issues beyond clearance; 13 noted a decrease in time needed for each athlete exam. Over 90% of athletes who used the web site found it "easy" or "moderately easy" to access and complete. Initial assessment of this new PPE format shows good athlete compliance, improved exam efficiency and a strong increase in subjective physician satisfaction with the quality of screening and medical care provided. The data indicate a need for improvement of routine health maintenance in this population. The database offers opportunities to study trends, risk factors, and results of interventions.

Adolescent↗

PubMed1999

Perceptions of physical fitness in patients with heart failure.

This study examined the relationship between perceived physical condition and measured physical fitness and activity levels in 40 patients with moderate heart failure (HF). Self rated physical condition, physical activity, self efficacy, and quality of life were evaluated by self administered questionnaires. Functional capacity was examined by cardiopulmonary exercise testing and 6 minute walk test. We found that physical activity levels were low. Participation in moderate intensity recreational activity and physical fitness were associated with self efficacy. Perceived physical condition was associated with emotional well being and levels of energy and fatigue. We conclude that self efficacy may reflect physical condition and physical activity levels in this sample of HF patients and may be a simple indicator of physical ability. Because of the association between perceived physical condition and emotional well being, caution must be taken when using self reports of physical condition. Further study is needed to explore these relationships.

Adult↗

PubMed1998

A review of the incorporation of complementary and alternative medicine by mainstream physicians.

BACKGROUND: Studies suggest that between 30% and 50% of the adult population in industrialized nations use some form of complementary and/or alternative medicine (CAM) to prevent or treat a variety of health-related problems. METHOD: A comprehensive literature search identified 25 surveys conducted between 1982 and 1995 that examined the practices and beliefs of conventional physicians with regard to 5 of the more prominent CAM therapies: acupuncture, chiropractic, homeopathy, herbal medicine, and massage. Six studies were excluded owing to their methodological limitations. RESULTS: Across surveys, acupuncture had the highest rate of physician referral (43%) among the 5 CAM therapies, followed by chiropractic (40%) and massage (21%). Rates of CAM practice by conventional physicians varied from a low of 9% for homeopathy to a high of 19% for chiropractic and massage therapy. Approximately half of the surveyed physicians believed in the efficacy of acupuncture (51%), chiropractic (53%), and massage (48%), while fewer believed in the value of homeopathy (26%) and herbal approaches (13%). CONCLUSIONS: This review suggests that large numbers of physicians are either referring to or practicing some of the more prominent and well-known forms of CAM and that many physicians believe that these therapies are useful or efficacious. These data vary considerably across surveys, most likely because of regional differences and sampling methods, suggesting the need for more rigorous surveys using national, representative samples. Finally, outcomes studies are needed so that physicians can make decisions about the use of CAM based on scientific evidence of efficacy rather than on regional economics and cultural norms.

Acupuncture Therapy↗

PubMed1998

Effects of diet and exercise in men and postmenopausal women with low levels of HDL cholesterol and high levels of LDL cholesterol.

BACKGROUND: Guidelines established by the National Cholesterol Education Program (NCEP) promote exercise and weight loss for the treatment of abnormal lipoprotein levels. Little is known, however, about the effects of exercise or the NCEP diet, which is moderately low in fat and cholesterol, in persons with lipoprotein levels that place them at high risk for coronary heart disease. METHODS: We studied plasma lipoprotein levels in 180 postmenopausal women, 45 through 64 years of age, and 197 men, 30 through 64 years of age, who had low high-density lipoprotein (HDL) cholesterol levels (< or =59 mg per deciliter in women and < or =44 mg per deciliter in men) and moderately elevated levels of low-density lipoprotein (LDL) cholesterol (>125 mg per deciliter but <210 mg per deciliter in women and >125 mg per deciliter but <190 mg per deciliter in men). The subjects were randomly assigned to aerobic exercise, the NCEP Step 2 diet, or diet plus exercise, or to a control group, which received no intervention. RESULTS: Dietary intake of fat and cholesterol decreased during the one-year study (P<0.001), as did body weight, in women and men in either the diet group or the diet-plus-exercise group, as compared with the controls (P<0.001) and the exercise group (P<0.05), in which dietary intake and body weight were unchanged. Changes in HDL cholesterol and triglyceride levels and the ratio of total to HDL cholesterol did not differ significantly among the treatment groups, for subjects of either sex. The serum level of LDL cholesterol was significantly reduced among women (a decrease of 14.5+/-22.2 mg per deciliter) and men (a decrease of 20.0+/-17.3 mg per deciliter) in the diet-plus-exercise group, as compared with the control group (women had a decrease of 2.5+/-16.6 mg per deciliter, P<0.05; men had a decrease of 4.6+/-21.1 mg per deciliter, P<0.001). The reduction in LDL cholesterol in men in the diet-plus-exercise group was also significant as compared with that among the men in the exercise group (3.6+/-18.8 mg per deciliter, P<0.001). In contrast, changes in LDL cholesterol levels were not significant among the women (a decrease of 7.3+/-18.9 mg per deciliter) or the men (10.8+/-18.8 mg per deciliter) in the diet group, as compared with the controls. CONCLUSIONS: The NCEP Step 2 diet failed to lower LDL cholesterol levels in men or women with high-risk lipoprotein levels who did not engage in aerobic exercise. This finding highlights the importance of physical activity in the treatment of elevated LDL cholesterol levels.

Adult↗

PubMed1998

Seven-year change in graded exercise treadmill test performance in young adults in the CARDIA study. Cardiovascular Risk Factors in Young Adults.

PURPOSE: Most studies of physical fitness change have been relatively small, not population-based, and lacking in women and nonwhites. The purpose of this analysis was to evaluate the 7-yr change in physical fitness in a biracial (black and white) population of young men and women. METHODS: We evaluated change in exercise treadmill test performance in a biracial (black and white) population of 1,962 young adults, ages 18-30 yr at baseline, who completed symptom-limited graded exercise treadmill tests at the baseline (1985-1986) and year 7 (1992-1993) examinations of the CARDIA study. RESULTS: Mean test duration decreased 58 s (9.5%) over 7 yr (black men, 13.6% decrease, white men, 7.4%; black women, 11.1%; white women, 7.0%). Mean time to heart rate 130 (WL130), a measure of submaximal performance, decreased 31 s (11.3%) (black men, 16.9%; white men, 10.0%; black women, 12.3%; white women, 6.1%). Baseline body mass index (BMI) and physical activity were not statistically significant predictors of test duration change in any race-gender group, but change in BMI and activity were. Seven-year weight gain >20 lbs (31% of cohort) was associated with a large decrease in fitness (18.5% decrease in mean duration, 21.8% decrease in WL130). CONCLUSION: These data suggest that fitness declines during young adulthood in blacks and whites and that fitness changes are related to changes in weight and physical activity.

Adult↗

PubMed1998

Activity Counseling Trial (ACT): rationale, design, and methods. Activity Counseling Trial Research Group.

The Activity Counseling Trial (ACT) is a multicenter, randomized controlled trial to evaluate the effectiveness of interventions to promote physical activity in the primary health care setting. ACT has recruited, evaluated, and randomized 874 men and women 35-75 yr of age who are patients of primary care physicians. Participants were assigned to one of three educational interventions that differ in amount of interpersonal contact and resources required: standard care control, staff-assisted intervention, or staff-counseling intervention. The study is designed to provide 90% power in both men and women to detect a 1.1 kcal.kg-1.day-1 difference in total daily energy expenditure between any two treatment groups, and over 90% power to detect a 7% increase in maximal oxygen uptake, the two primary outcomes. Primary analyses will compare study groups on mean outcome measures at 24 months post-randomization, be adjusted for the baseline value of the outcome measure and for multiple comparisons, and be conducted separately for men and women. Secondary outcomes include comparisons between interventions at 24 months of factors related to cardiovascular disease (blood lipids/lipoproteins, blood pressure, body composition, plasma insulin, fibrinogen, dietary intake, smoking, heart rate variability), psychosocial effect, and cost-effectiveness, and at 6 months for primary outcome measures. ACT is the first large-scale behavioral intervention study of physical activity counseling in a clinical setting, includes a generalizable sample of adult men and women and of clinical setting, and examines long-term (24 months) effects. ACT has the potential to make substantial contributions to the understanding of how to promote physical activity in the primary health care setting.

Adult↗